Derivation of the sinusoidal sweep vibration test levels for the Cosmic Background Explorer (COBE)

The Cosmic Background Explorer (COBE) Observatory was successfully launched on November 18, 1989 using a Delta l expendable launch vehicle. Prior to launch, COBE was subjected to sinusoidal sweep vibration testing in each of three axes in the 15 Hz to 40 Hz region. The tests were used to qualify COBE for the sustained periodic oscillation events that were expected to occur in flight for the Delta l launch vehicle. These events were called pre-MECO (Main Engine Cutoff) POGO and MECO-POGO. Pre-MECO POGO is also commonly called mini-POGO. This paper will describe the process used to derive the sinusoidal sweep test levels and will present a comparison of the actual COBE flight data versus the derived test levels. The results show that the derived test levels were sufficient to encompass the levels measured in flight for the COBE mission.